Sightings of anomalous big cats in Australia began more than 100 years ago.

In the Gippsland region of south-eastern Victoria, the origin of the cats is claimed to be American World War II airmen who brought cougars with them as mascots and released them in the Australian Bush. No conclusion has been reached, and photographic evidence is often difficult to interpret. The mass slaughter of sheep is often given as evidence to support the big cat theory. They are often killed by a clean puncture or slit in the throat. The animals' insides are then eaten precisely and with no mess, in the same way a big cat kills and eats its prey.

Several sets of video footage, claiming to show black panthers in the Australian bush, have proved to be large feral cats.

Claimed sightings of big cats and their effects have led to government studies of the Grampian Mountains Cougar and Gippsland Cat in Victoria, the Blue Mountains panther and Lithgow Panther in New South Wales.